Do you think it is appropriate to have a portion of the worship service dedicated to the giving, where we spend 5 to 10 minutes inspiring members to give, or should it be a silent passing of the baskets?
It depends on the group. Ritualizing the contribution is what most churches do. You are (rightly) asking whether we need to do this at all. Since there is no scripture on this, I view this as an area of liberty.
I prefer to give monthly, quarterly, or even annually. Our family sets money aside and gives in advance--that way we can’t spend it!
Anyway, the weekly talks do little for me, as I've already decided how much to give. I suppose they do help those who are not so disciplined in their finances, and may be valuable in such situations.
